Install and configure environment variables after uninstalling jdk in Linux

Install and configure environment variables after uninstalling jdk in Linux

Under the Linux operating system of CentOS 7.x, there will be a built-in openjdk environment. If we want to install the jdk environment ourselves, we need to uninstall the built-in openjdk environment.

Proceed as follows:

1. View the java environment

java -version

2. Query jdk

# 查看linux的jdk
rpm -qa | grep jdk

3. Delete jdk

# 移除openjdk
yum -y remove java-openjdk-xxxxx

java-openjdk-xxxxx : is the openjdk that needs to be deleted

After deleting the built-in openjdk environment, we start to install our jdk.

4. Get the tarball from Windows or other machines

# 将文件传出Linux中的用户目录
scp D:/dsoftmanager/jdk-8u151-linux-x64.tar.gz root@192.168.108.5:/home/zhang

D:/dsoftmanager/jdk-8u151-linux-x64.tar.gz: The location of the tar package directory of the A machine

[email protected]:/home/zhang: The directory location where the linux machine stores the tar

5. Unzip the tar package to the specified directory

# 创建java目录
mkdir /usr/java

# 将文件复制到java目录
cp /home/zhang/jdk-8u151-linux-x64.tar.gz  /usr/java

# 进入/usr/java
cd /usr/java

# 解压缩
tar -zxvf jdk-8u151-linux-x64.tar.gz 

6. Configure environment variables

# 打开配置文件
vim /etc/profile

Open /etc/profilethe file, and at the end of the file, put the following configuration information:

# 配置java环境

JAVA_HOME=/usr/java/jdk1.8.0_151
PATH=$PATH:$JAVA_HOME/bin:/usr/bin:/usr/sbin:/bin:/sbin:/usr/X11R6/bin
CLASSPATH=.:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar
export  JAVA_HOME  PATH  CLASSPATH

7. Restart the machine

# 立即重启机器
shutdown -r now

If you do not restart, the configuration will not take effect.

8, java environment test

# 测试java环境是否安装成功
java -version
javac -version

The following information appears, indicating that the installation is successful.

[zhang@localhost Desktop]$ java -version
java version "1.8.0_151"
Java(TM) SE Runtime Environment (build 1.8.0_151-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.151-b12, mixed mode)

[zhang@localhost Desktop]$ javac -version
javac 1.8.0_151